732强酸性阳离子树脂催化合成盐酸维生素B1

以硫羟硫胺为原料,经双氧水氧化得硫酸维生素B1(VB1·H2SO4);VB1·H2SO4经纯化水稀释后,流经732强酸型阳离子交换树脂,用稀盐酸洗脱,浓缩后用85%乙醇重结晶得盐酸VB1,其结构经1H NMR,13C NMR,MS和元素分析确证。     

New and Convergent Synthesis of Osimertinib

New and convergent synthetic route of osimertinib is described on a dozen of grams scale. A key cyclization of 1‐(4‐((2‐(dimethylamino)ethyl)(methyl)amino)‐2‐methoxy‐5‐nitrophenyl)guanidine and 3‐(dimethylamino)‐1‐(1‐methyl‐1H‐indol‐3‐yl)prop‐2‐en‐1‐one is adopted to give the 4‐(1H‐indol‐3‐yl)‐N‐phenylpyrimidin‐2‐amine structure. Osimertinib is prepared in 40.4% yield over six steps and 99.1% purity (HPLC). Purification methods of the intermediates involved in the route are also given.     

One-Pot Synthesis of 1H-Benzimidazole Derivatives Using Thiamine Hydrochloride as a Reusable Organocatalyst

A simple and efficient one-pot synthesis of 1H-benzimidazole derivatives using thiamine hydrochloride (VB₁) as the organocatalyst from o-phenylenediamine and aldehyde in dimethylformamide is described. Compared to classical reaction conditions, this new method consistently has the advantages of excellent yields, metal-ion-free procedure, and good recovery and reusablity of catalyst.     

A Facile and Convergent Synthesis of Sarmentosin

Abstract

A concise synthesis of sarmentosin (1) starting from butane-1,2,4-triol-1,2-acetonide is described. This convergent route can also be employed for the preparation of sarmentosin analogues for structure-activity relationship studies.     

合成盐酸氨溴索的新方法

以邻氨基苯甲酸甲酯（1）为起始原料,与溴素发生溴化反应制得2-氨基-3,5-二溴苯甲酸甲酯（2）。2经红铝试剂还原制得2-氨基-3,5-二溴苯甲醛（3）; 3经还原胺化制得氨溴索（4）; 4盐酸化得到盐酸氨溴索（5）,总收率60.8%,其结构经¹H NMR确证。     

A Novel Synthesis of Difloxacin Hydrochloride

Difloxacin, the third generation of new quinolone antibiotics, has broad-spectrum in vitro activity and excellent potency in vivo and has been found to be against gram-positive cocci, gram-negative bacteria, anaerobe, mycoplasm, chlamydia1,2. As described previously, high reaction temperature and hazardous reagents are the defects of the methods for preparation of difloxacin3,4. We have developed a new synthetic method as shown in the Scheme. 2,4-Dichloro-5-fluoro-acetophenone 1 was used as …     

A Short Convergent Synthesis of (±) Patulolide A

A short, convergent synthesis of (±) patulolide A, a 12-membered macrolide with high antifungal activities is hereby reported. It has been achieved in 10 steps from 1-bromopentanal and 4-hydroxypent-1-yne.     

A Convenient Synthesis of 4-Nitrophenethylamine Hydrochloride

Abstract

A short, convenient, and efficient synthesis of 4-nitrophenethylamine hydrochloride is described. The key step involved removal of water from 4-nitrophenylalanine monohydrate followed by decarboxylation.     

A Convergent Route for the Synthesis of AF—5

AF-5 was synthesized through a convergent method. The key step was the Robinson annulation using a key intermediate pentyl vinyl ketone.     

一种制备盐酸西那卡塞的新方法

（R）-1-萘乙胺与丙烯酰氯发生亲核取代反应制得酰胺（2）; 2与3-三氟甲基碘苯经Heck偶联反应制得α,β-不饱和酰胺（3）; 3经两次还原反应后再与盐酸成盐合成了盐酸西那卡塞,总收率40%,纯度>99.5%, ee值>99.9%,其结构经¹H NMR和¹³C NMR确证。     

A Convergent Approach to Dibenzodioxocinones: Synthesis of Racemic Penicillide

A convergent approach to dibenzodioxocinones was explored, thereby racemic penicillide ((±)‐ 1a ) could be obtained in 13 steps in 4.2% overall yield, based on 5‐amino‐2‐methylphenol ( 5 ) (Schemes 2–4).     

Preparation and Spectroscopic Studies of Charge-Transfer Complexes of Thiamine Hydrochloride with Different Electron Acceptor

Abstract—Electronic interactions associated with charge transfer complexes formation of iodine, chloranilic acid (H₂CA) and 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) with vitamin B1 have been studied spectrophotometrically. The accumulated data indicated formation of CT-complexes of the general formula [(VB1)(acceptor) _n ], (n = 1 or 2). The 1 : 2 and 1 : 1 donor: acceptor molar ratios were calculated on the basis of elemental analysis and photometric titrations. The solid complexes were prepared and characterized by their conductivity, UV-Vis, IR, and ¹H NMR spectra, and thermogravimetric analyses (TGA, DTG). The characteristic physical constants (K_CT, ε_CT, μ, ΔG, I_p, f, E_CT) of the formed CT-complexes were determined to be strongly dependent on nature of the electron acceptors.

     

盐酸达泊西汀的合成

以3-氯苯丙酮为起始原料,经不对称还原、烃化、O-甲磺酰化、SN2二甲胺化和成盐合成了盐酸达泊西汀,总收率39.9%,其结构经1H NMR和MS确证.     

盐酸尼非卡兰的合成

以N，N′-二甲基脲为原料，经氰乙酸环合、乙醇胺脱氨、二氯亚砜氯化3步反应合成了关键中间体6-(2-氯乙基)胺基-1，3-二甲基-嘧啶二酮(7)。7再与：N-(2-羟乙基)-3-(4-硝基苯基)丙胺反应得抗心律失常药盐酸尼非卡兰，总收率为48．0％(以N，N′-二甲基脲计)，其结构经NMR和MS确认。     

盐酸奥洛他定的合成

以对羟基苯乙酸和苯酞为原料,经缩合、环合、Wittig反应等合成了抗过敏药盐酸奥洛他定,总收率12.5%,其结构经1H NMR, IR和MS确证.